Fossils can be used to match up rock layers. As organisms change over time, they look different. Older fossils will look different than younger fossils. Some organisms only survived for a short time before going extinct. Knowing what organisms looked like at certain times also helps date rock layers. Some fossils are better than others for this use. The fossils that are very distinct at certain times of Earths history are called index fossils. Index fossils are commonly used to match rock layers. You can see how this works in Figure 2.30. If two rock layers have the same index fossils, then they're probably about the same age. 

What kind of fossils are used to date rock layers?


Alexis-Charles-Henri Clerel de Tocqueville (French: [aleksi SaRl aRi kleRel d@ tokvil]; 29 July 1805 - 16 April 1859) was a French political thinker and historian best known for his works Democracy in America (appearing in two volumes: 1835 and 1840) and The Old Regime and the Revolution (1856). In both of these, he analyzed the improved living standards and social conditions of individuals, as well as their relationship to the market and state in Western societies. Democracy in America was published after Tocqueville's travels in the United States, and is today considered an early work of sociology and political science. Tocqueville was active in French politics, first under the July Monarchy (1830-1848) and then during the Second Republic (1849-1851) which succeeded the February 1848 Revolution. He retired from political life after Louis Napoleon Bonaparte's 2 December 1851 coup, and thereafter began work on The Old Regime and the Revolution. He argued that the importance of the French Revolution was to continue the process of modernizing and centralizing the French state which had begun under King Louis XIV. The failure of the Revolution came from the inexperience of the deputies who were too wedded to abstract Enlightenment ideals. Tocqueville was a classical liberal who advocated parliamentary government, but was skeptical of the extremes of democracy. 

How did the writer of Democracy in America feel about the extremes of democracy?


The Mummy 's Shroud is set in 1920 and tells the story of a team of archaeologists who come across the lost tomb of the boy Pharaoh Kah-To-Bey . The story begins with a flash back sequence to Ancient Egypt and we see the story of how Prem , a manservant of Kah-To-Bey , spirited away the boy when his father was killed in a palace coup and took him into the desert for protection . Unfortunately , the boy dies and is buried . The story then moves forward to 1920 and shows the expedition led by scientist Sir Basil Walden and business man Stanley Preston finding the tomb . They ignore the dire warning issued to them by Hasmid , a local Bedouin about the consequences for those that violate the tombs of Ancient Egypt and remove the bodies and the sacred shroud . Sir Basil is bitten by a snake just after finding the tomb . He recovers , but has a relapse after arriving back in Cairo . Preston takes advantage of this and commits him to an insane asylum , to take credit for finding the tomb and Prince 's mummy himself . Meanwhile , after being placed in the Cairo Museum , the mummy of Prem is revived when Hasmid chants the sacred oath on the shroud . The mummy then proceeds to go on a murderous rampage to kill off the members of the expedition , beginning with Sir Basil after he escapes from the asylum . One by one , those who assisted in removing the contents of the tomb to Cairo are eliminated by such grisly means as strangulation , being thrown out of windows , and having photographic acid thrown in their face . 


What happens to those who violated the tombs?